1. Field of the Invention
The present invention relates to an air bag for a motor vehicle, and more particularly to a multi-chambered side impact air bag that is deployed in response to a vehicle impact event.
2. Background Art
Multi-chambered air bags are known in the vehicle air bag art, such as that disclosed in U.S. patent application Ser. No. 10/382,642. In FIG. 35 of the application referenced above, an air bag is shown having first and second chambers. The first chamber is disposed behind the shoulder of a seat occupant and the second chamber is disposed in front of and below the first chamber. Gas is supplied to the first and second chambers through first and second small holes of different total opening areas at different flow rates. Due to the difference of the gas flow rates, the first and second chambers are inflated such that the internal pressure of the first chamber is lower than the internal pressure than the second chamber.
Applicant of the present invention has discovered that inflating a first or rearward chamber of a side air bag to a lower pressure than an adjacent front chamber is not desirable. More specifically, such air bag configurations do not provide adequate occupant protection when a vehicle seat moves to a different position, such as when the floor panel or seat of a vehicle is deformed by the impact event. In such situations, the seat occupant may not move in unison with the seat. As a result, the occupant will benefit from higher rear air bag pressures that help separate the occupant from interior vehicle surfaces.
Before Applicant's invention, there was a need for an improved side impact air bag for a motor vehicle. In addition, there was a need for a side impact air bag that addresses the dynamics of vehicle components, such as the translation of a seat, in relation to a seat occupant. In addition, there was a need for an air bag that helps move the seat occupant with the vehicle seat, yet provides different levels of support or cushioning to reduce shoulder, abdominal, and thoracic rib displacements of a seat occupant to reduce the likelihood of injury. Problems associated with the prior art as noted above and other problems are addressed by Applicant's invention as summarized below.